This paper empirically examines one aspect of Basil Bernstein's sociolinguistic account of educational failure, a code thesis wherein a restricted code is defined as giving access only to "particularistic" meanings and an elaborated code is defined as giving access also to "universalistic" meanings. According to Bernstein, because working class children usually have only a restricted code, and the school as an institution is predicated on elaborated codes, then middle class children succeed by virtue of their elaborated code background and working class children fail. Two groups of students from the first year of an upper school in southern England, one with primarily non-manual backgrounds, the other with primarily manual backgrounds, were observed in math and science classrooms, through informal discussions with teachers, and through school records and reports to determine which of Bernstein's two codes appeared to underlie the disciplinary and pedagogic techniques of the teachers of the classes observed. The problem of method (especially with respect to coding of utterances for statistical analysis) are discussed throughout. Findings show that in terms of the indicators for both regulative and instructional contexts, the observed math and science curriculums appeared to be predicated on a restricted rather than an elaborated code for both classes of students. This conclusion suggests that Bernstein's emphasis on certain pupils lacking an elaborate code in accounting for working class failure and middle class success, is misplaced. Further empirical study, especially in the arts curriculum, is suggested. (Author/MHP)